What is PROTOLON XPRT-LWL (N)TSKCGEWOEU 6/10KV: An In-Depth Engineering Analysis of the Fibre-Optic Hybrid Medium Voltage Reeling Cable
PROTOLON XPRT-LWL (N)TSKCGEWOEU 6/10KV is a flexible medium voltage opto-power reeling cable designed for high to extreme mechanical stresses: high travel speeds, dynamic tensile loads, multiple changes of direction into different planes, churning on running over rollers and torsional stress. Its defining feature is the integration of a protected optical element with 24 singlemode E9 fibres — designated 24E9LWL — into a 6/10 kV three-core rubber reeling cable with split earth conductors. The result is a single cable on a single reel that simultaneously carries medium voltage power, the protective earth function and a high-bandwidth, EMI-immune fibre-optic data backbone for crane automation, CCTV, remote operation and terminal operating system connectivity on fast-moving container cranes and large mobile equipment.
Definition and application
1. What is PROTOLON XPRT-LWL (N)TSKCGEWOEU 6/10KV?
PROTOLON XPRT-LWL (N)TSKCGEWOEU 6/10KV is a flexible medium voltage reeling cable for high to extreme mechanical stress applications, combined with an integrated fibre-optic data subsystem. It belongs to the same engineering family as the classic (N)TSCGEWOEU medium voltage reeling cables, but it answers a question that pure power cables cannot: how do you bring gigabit-class data communication to a machine that travels hundreds of metres on a motorized cable reel, without adding a second reel, a second cable path and a second maintenance object?
The answer is structural integration. Three medium voltage power cores supply the drives, hoists and auxiliary systems of the machine. Two split protective earth conductors occupy two of the three interstices between the cores. The third interstice carries a protected optical element with 24 singlemode E9 fibres, giving the machine a permanent optical link for PLC and drive communication, IP cameras and OCR gates, anti-sway and positioning systems, remote operation stations and terminal operating system (TOS) integration — all immune to the electromagnetic environment created by the medium voltage cores running centimetres away.
Typical equipment includes ship-to-shore (STS) container cranes, rail-mounted gantry cranes (RMG), electrified rubber-tyred gantry cranes (RTG-E), ship loaders and unloaders, stacker-reclaimers, bucket-wheel excavators, spreaders and other large moving machines in ports, terminals, bulk handling plants and open-cast mining where medium voltage power and high-bandwidth data must travel together over a reeling system.
Technical thesis
Engineering argument: the core value of PROTOLON XPRT-LWL 6/10kV is consolidation under extreme mechanical duty. One reel, one cable path and one cable management system replace what would otherwise be two independent reeling systems — a medium voltage power reel and a separate fibre-optic reel — that must be purchased, installed, synchronized, inspected and stocked with spares separately. Every elimination of a moving subsystem on a crane is an elimination of a failure mode; the hybrid design moves the integration problem from the crane builder’s drawing board into the cable cross-section, where it is solved once, at the factory.
1.1 Application profile decoded
| Application dimension | Datasheet description | Engineering meaning |
|---|---|---|
| Cable category | Medium voltage opto-power reeling cable | Flexible 6/10 kV reeling cable with integrated fibre-optic element for mobile power and data supply. |
| Mechanical stress class | High to extreme mechanical stresses | Designed for the most severe reeling duty class, not for light or occasional movement. |
| Travel speed | High travel speeds | Suitable for fast-moving gantry cranes and high-speed reel pick-up and pay-off. |
| Dynamic tensile loads | Starting, braking, acceleration, reel tension | The cable and the optical element must survive repeated dynamic tension events, not only static hang loads. |
| Direction changes | Multiple changes of direction into different planes | Suitable for complex roller arrangements, guide sheaves and multi-plane cable paths. |
| Roller operation | Churning on running over rollers | Sheath and internal structure resist roller churning, compression and abrasion. |
| Torsional stress | ±25°/m class torsion duty | Reinforcement and stranding geometry control twist damage to both copper and glass. |
| Data subsystem | 1x(24E9LWL) optical element | 24 singlemode fibres for automation, CCTV, remote control and TOS communication. |
| Typical equipment | Fast-moving container cranes and large mobile equipment | STS, RMG, RTG-E cranes, ship unloaders, stacker-reclaimers, mining machines. |
Type designation and standards
2. Reading the Designation: (N)TSKCGEWOEU and 24E9LWL Explained
Harbour and crane engineers usually meet this cable for the first time as a type code in a crane specification. The designation follows the German VDE convention for heavy rubber reeling cables. The table below gives the working reading used in practice for this cable family.
| Code element | Working reading | What it tells the engineer |
|---|---|---|
| (N) | Standards-derived type | Design based on the VDE standard family (DIN VDE 0250-813) with manufacturer-specific enhancements. |
| T | Trommel — reeling duty | Built for motorized cable reels, not only festoon or fixed installation. |
| S | Heavy duty | Heavy rubber-sheathed construction for severe mechanical service. |
| K | Combined (hybrid) design | Within this family, the K distinguishes the combined opto-power construction of the XPRT-LWL version from the standard (N)TSCGEWOEU power-only type. |
| C | Protective conductor concept | Split protective earth conductors arranged in the interstices around the power cores. |
| G | Rubber insulation and sheathing | EPR insulation with elastomer sheaths — the basis of cold flexibility and reeling life. |
| E / W | Enhanced thermal design | Increased heat resistance for 90°C conductor operation. |
| OE (Ö) | Oil resistant | Sheath compound tested for oil resistance (DIN EN 60811-404 / IEC 60811-404 class testing). |
| U | Flame retardant | Sheath does not propagate flame — essential on cranes and in tunnels and machine houses. |
2.1 What does 24E9LWL mean?
| Element | Meaning | Engineering relevance |
|---|---|---|
| 24 | Fibre count | 24 optical fibres — enough for redundant rings, CCTV, automation, remote operation and spare capacity. |
| E9 | Singlemode fibre, 9/125 µm class | Singlemode glass of the ITU-T G.652 class with a nominal 9 µm core — low attenuation at 1310/1550 nm and effectively unlimited bandwidth-distance product for crane-scale links. |
| LWL | Lichtwellenleiter — optical fibre (German) | Marks the cable as a fibre-optic hybrid in German-convention type codes; international datasheets often write FO or 24FO for the same concept. |
2.2 Standards landscape
| Standard / reference | Scope in this cable | Engineering significance |
|---|---|---|
| DIN VDE 0250-813 | General design basis | The reference standard for heavy medium voltage rubber reeling cables of this family. |
| DIN VDE 0298-4 | Electrical parameters | Current-carrying capacity reference for rubber cables (Table 15, 30°C ambient, in air). |
| DIN EN 60228 / IEC 60228 / VDE 0295 | Conductor classes | Very finely stranded tinned copper, class FS — the flexibility basis of reeling life. |
| VDE 0298-3 | Bending radii rules | Source of the 6×D fixed / 10×D moving / 20×D S-type direction change rules. |
| DIN EN 60811-404 / IEC 60811-404 | Chemical behaviour | Oil immersion testing of the sheath compounds. |
| IEC 60793 / IEC 60794 / ITU-T G.652 class | Optical fibre and FO unit | Singlemode fibre geometry, attenuation classes and optical cable element testing conventions. |
| Reversed bending / roller bending / torsion testing | Mechanical parameters | Confirms suitability for reel, roller and multi-plane direction change duty. |
Cable construction
3. Construction Analysis: Class FS Conductors, EPR Field Control, Split Earths and the Protected Optical Element
The construction follows the proven architecture of high mechanical stress medium voltage reeling cables, with one decisive addition: the third interstice, which in a standard (N)TSCGEWOEU would carry the third split earth conductor, is occupied by the protected fibre-optic element. The protective earth function is concentrated into two larger split conductors in the remaining two interstices — hence the 2×25/2, 2×35/2, 2×50/2 … 2×150/2 earth notation in the size list instead of the familiar 3x…/3.
Why the fibres live in the interstice
Engineering argument: in an opto-power reeling cable, the most fragile element is not copper but glass. Copper yields and recovers; glass fractures at strain levels far below copper’s elastic limit, and even sub-critical strain shows up immediately as attenuation. Placing the optical unit in the interstice between the three cores puts it in the most geometrically protected position of the cross-section — surrounded on all sides by compliant insulated cores that absorb radial roller pressure — while the strain-decoupled unit design keeps fibre elongation below the proof-test margin during 30 N/mm² dynamic tension events. The hybrid cable is therefore not “a power cable with fibres added”; it is a structure engineered around the survival of the glass.
Electrical and thermal parameters
4. Electrical and Thermal Parameters: 6/10 (12) kV, 17 kV Test Voltage, 90°C Conductor Temperature
The cable is rated U0/U (Um) = 6/10 (12) kV with a nominal voltage U of 10000 V and an AC test voltage of 17 kV, in line with the established values of the 6/10 kV class in this reeling cable family. Maximum conductor temperature is 90°C in continuous operation and 250°C under short circuit. The fixed installation ambient range is -50°C to +80°C; for flexible (moving) operation the range is -35°C to +80°C.
| Parameter | Value | Engineering interpretation |
|---|---|---|
| Rated voltage U0/U (Um) | 6/10 (12) kV | Suited to 10 kV class medium voltage mobile power systems. |
| Test voltage | 17 kV AC | Verification level of the 6/10 kV insulation system. |
| Nominal voltage U | 10000 V | Corresponds to 10 kV distribution levels common on STS and RMG cranes. |
| Max. conductor temperature | 90°C | Continuous operation limit of the EPR insulation system. |
| Max. short-circuit temperature | 250°C | Basis for short-time thermal withstand verification. |
| Ambient, fixed installation | -50°C to +80°C | For static runs and fixed cable sections. |
| Ambient, flexible operation | -35°C to +80°C | The verification boundary for dynamic reel, roller and travel operation. |
Medium voltage insight
Engineering argument: a 6/10 kV reeling cable is not “a low voltage cable with thicker insulation”. The semi-conductive field control layers, the easy-strip screen interface and the termination workmanship determine long-term partial-discharge behaviour, and on a reeling cable every one of these interfaces is also a mechanical component that flexes thousands of times per year. Selection therefore always has to verify the electrical system (voltage, test voltage, termination method) and the mechanical system (tension, bending, torsion) together — neither alone is sufficient.
The optical subsystem
5. The Optical Subsystem: Why 24 Singlemode E9 Fibres, and What They Replace
The choice of singlemode E9 fibre (9/125 µm class, ITU-T G.652 family) rather than multimode or copper communication pairs is a deliberate engineering decision with three independent justifications.
First, electromagnetic immunity. Optical fibre is fully dielectric. Copper communication pairs laid inside a medium voltage cable would run centimetres from cores switching hundreds of amperes through variable-frequency drives — a worst-case environment for induced interference, requiring screening, isolation transformers and still suffering bandwidth and distance limits. Glass simply does not participate in the electromagnetic environment, and it additionally provides galvanic isolation between the moving machine and the shore-side network, eliminating earth-loop and transferred-potential issues across the link.
Second, bandwidth-distance product. Singlemode E9 fibre supports crane runs of any realistic length — and onward terminal backbone distances of kilometres — at 1310/1550 nm with low attenuation and no modal bandwidth ceiling. Multimode fibre would work on a short crane run today, but limits link speed upgrades tomorrow; singlemode makes the reeling cable the last component anyone needs to touch when the terminal upgrades from 1 Gbit/s to 10, 25 or 100 Gbit/s optics.
Third, fibre count as redundancy and headroom. A modern automated crane typically consumes fibres in pairs: redundant PLC/drive rings, CCTV and OCR cameras, remote operation video, access control, condition monitoring. Twenty-four fibres allow dual-path redundancy, dark-fibre spares for future systems and immediate recovery capacity if individual fibres are damaged at terminations — without ever opening the cable.
| Criterion | Copper communication pairs | Multimode fibre (50/125) | Singlemode E9 (this cable) |
|---|---|---|---|
| EMI sensitivity next to MV cores | High — needs screening, still limited | None (dielectric) | None (dielectric) |
| Galvanic isolation crane ↔ shore | No | Yes | Yes |
| Bandwidth-distance product | Low — Mbit/s class over crane runs | Medium — modal bandwidth limited | Effectively unlimited for crane-scale links |
| Onward connection to terminal backbone | Requires media conversion | Often requires conversion to SM backbone | Direct splice to singlemode backbone |
| Upgrade path (10/25/100 Gbit/s) | No | Restricted | Yes — change optics, keep cable |
| Long-term role in the cable | Legacy | Transitional | Future-proof standard |
5.1 Terminating the optical element on a reeling system
On a motorized reel, the power cores terminate through slip rings; the fibres terminate through a fibre-optic rotary joint (FORJ) mounted on the reel axis, or — on some reel designs — through a free inner length with a splice box on the drum. Both ends of the optical element are normally fusion-spliced into splice cassettes and patched to the crane and shore networks with standard singlemode connectors. The practical design rules are: respect the cable’s moving bending radius everywhere the fibres travel, provide strain-free routing of the breakout, and keep an attenuation budget reserve for the FORJ and splices when calculating the optical link.
Chemical and environmental resistance
6. Chemical and Environmental Performance: Oil, Ozone, UV and Seawater
Port and terminal duty exposes a reeling cable to sunlight, rain, salt mist, seawater splash, hydraulic and lubricating oils, ozone from nearby electrical equipment and continuous mechanical abrasion — simultaneously. The chloroprene-based PROTOFIRM-class outer sheath (special compound > 5GM5) is the component that converts laboratory ratings into service life under this combined exposure.
| Environmental property | Status | Engineering value |
|---|---|---|
| Oil resistance | Yes (IEC 60811-404 class testing) | Withstands hydraulic oil, gear oil and industrial contamination on quays and machine houses. |
| Ozone resistance | Yes | Prevents sheath cracking near MV switchgear and drives. |
| UV resistance | Yes | Long-term outdoor exposure on open quay and stockyard equipment. |
| Seawater resistance | Yes | Quay edge, splash zone and salt-mist atmospheres. |
| Flame retardance | Yes (U designation) | No flame propagation along the cable route. |
| Outer sheath compound | PCP, PROTOFIRM class, > 5GM5 | The abrasion and tear resistance basis of reeling service life. |
Mechanical parameters
7. Mechanical Parameters: ±25°/m Torsion, 20/30 N/mm² Tensile Rules, VDE 0298-3 Bending Radii
The mechanical rules of the family apply: permissible torsional stress ±25°/m; permanent tensile rule 20 N/mm² static and 30 N/mm² dynamic, referred to the total power core cross-section. Gantry reeling operation carries no general speed restriction; for travel speeds above 240 m/min, consultation with the cable manufacturer is recommended. Bending radii follow VDE 0298-3: 6×D for fixed installation, 10×D for moving operation, and a minimum of 20×D between S-type direction changes.
| Mechanical parameter | Value / rule | Engineering significance |
|---|---|---|
| Torsional stress | ±25°/m | Covers multi-plane direction changes and reel-induced twist; also protects the optical element from twist deformation. |
| Static tensile rule | 20 N/mm² | Continuous operation and normal tension verification. |
| Dynamic tensile rule | 30 N/mm² | Starting, braking, acceleration and dynamic shock verification. |
| Gantry reeling speed | No general restriction | High-speed systems still require project-level verification. |
| Above 240 m/min | Consult the cable manufacturer | Ultra-high-speed reels need manufacturer-level confirmation. |
| Bending radius, fixed | 6 × D | For static routing sections. |
| Bending radius, moving | 10 × D | For reel, roller and dynamic travel sections — also the protection rule for fibre attenuation. |
| S-type direction change spacing | 20 × D minimum | For multi-roller, multi-plane guidance systems. |
One bending rule, two failure mechanisms
Engineering argument: on a power-only reeling cable, an undersized roller shortens life slowly through sheath and insulation fatigue. On an opto-power cable, the same undersized roller shows up immediately as optical attenuation — macrobending loss in singlemode fibre rises steeply once the bend radius falls below the design value. The 10×D moving radius is therefore not a conservative convenience; it is the simultaneous protection rule for thirty-year copper life and day-one optical performance, and it should be enforced at every sheave, roller and reel flange in the system.
Basic cable properties
8. Dimensional Range: From 3×25+2×25/2 +1x(24E9LWL) to 3×300+2×150/2 +1x(24E9LWL)
The 6/10 kV XPRT-LWL range spans power core sizes from 25 mm² to 300 mm², covering the full power spectrum from auxiliary mobile machines to the largest ship-to-shore cranes. Every size carries the same 24-fibre singlemode element, so data capability is constant across the range while power capability scales with cross-section. Across the range, the maximum outer diameter doubles (44.3 mm to 89.2 mm) while weight grows by a factor of about 5.7 (2800 to 15880 kg/km) — a reminder that for large sizes, cable self-weight on long lifts becomes a first-order term in the tension calculation.
| Basic construction | SAP code | External code | Conductor diameter mm | Cable diameter min mm | Cable diameter max mm | Cable weight kg/km |
|---|---|---|---|---|---|---|
| 3×25+2×25/2 +1x(24E9LWL) | 20470343 | — | 7.1 | 41.3 | 44.3 | 2800 |
| 3×35+2×25/2 +1x(24E9LWL) | 20470342 | — | 8.3 | 43.1 | 46.1 | 3150 |
| 3×50+2×25/2 +1x(24E9LWL) | 20470341 | — | 9.9 | 46.0 | 49.0 | 3800 |
| 3×70+2×35/2 +1x(24E9LWL) | 20460299 | 5DK4618 | 11.8 | 52.0 | 55.0 | 5000 |
| 3×95+2×50/2 +1x(24E9LWL) | — | — | 13.8 | 56.1 | 60.1 | 6300 |
| 3×120+2×70/2 +1x(24E9LWL) | — | — | 15.4 | 60.9 | 64.9 | 7660 |
| 3×150+2×70/2 +1x(24E9LWL) | 20478571 | — | 17.2 | 63.2 | 67.2 | 8700 |
| 3×185+2×95/2 +1x(24E9LWL) | — | — | 19.0 | 69.3 | 73.3 | 10690 |
| 3×240+2×120/2 +1x(24E9LWL) | — | — | 21.8 | 76.7 | 80.7 | 13410 |
| 3×300+2×150/2 +1x(24E9LWL) | — | — | 24.4 | 84.2 | 89.2 | 15880 |
Derived electrical and mechanical properties
9. Derived Selection Table: Tensile Limits, Moving Bending Radii, Conductor Resistance and Ampacity
For project pre-selection, the table below applies the published family rules to each size: maximum tensile force = 20 N/mm² × total power core cross-section; maximum tensile force during acceleration = 30 N/mm² × total power core cross-section; minimum moving bending radius = 10 × maximum cable diameter; conductor resistance per IEC 60228 for class 5/6 tinned copper; current-carrying capacity per VDE 0298-4 Table 15 (30°C ambient, rubber cable in air). Final project values are always confirmed against the issued datasheet for the specific construction.
| Basic construction | Max tensile force N | Max tensile during acceleration N | Min moving bending radius mm | Conductor resistance 20°C Ω/km | Current-carrying capacity A |
|---|---|---|---|---|---|
| 3×25+2×25/2 +1x(24E9LWL) | 1500 | 2250 | 443 | 0.795 | 139 |
| 3×35+2×25/2 +1x(24E9LWL) | 2100 | 3150 | 461 | 0.565 | 172 |
| 3×50+2×25/2 +1x(24E9LWL) | 3000 | 4500 | 490 | 0.393 | 215 |
| 3×70+2×35/2 +1x(24E9LWL) | 4200 | 6300 | 550 | 0.277 | 265 |
| 3×95+2×50/2 +1x(24E9LWL) | 5700 | 8550 | 601 | 0.210 | 319 |
| 3×120+2×70/2 +1x(24E9LWL) | 7200 | 10800 | 649 | 0.164 | 371 |
| 3×150+2×70/2 +1x(24E9LWL) | 9000 | 13500 | 672 | 0.132 | 428 |
| 3×185+2×95/2 +1x(24E9LWL) | 11100 | 16650 | 733 | 0.108 | 488 |
| 3×240+2×120/2 +1x(24E9LWL) | 14400 | 21600 | 807 | 0.0817 | 574 |
| 3×300+2×150/2 +1x(24E9LWL) | 18000 | 27000 | 892 | 0.0654 | 660 |
Comparative analysis
10. Comparative Analysis: Hybrid vs Standard Power Cable, and One Reel vs Two
10.1 (N)TSKCGEWOEU XPRT-LWL vs standard (N)TSCGEWOEU 6/10 kV
| Comparison item | Standard (N)TSCGEWOEU 6/10kV | PROTOLON XPRT-LWL (N)TSKCGEWOEU 6/10kV | Engineering reading |
|---|---|---|---|
| Earth conductor arrangement | 3 split earths in 3 interstices (x/3) | 2 split earths in 2 interstices (x/2) | The earth function is concentrated into two larger conductors to free one interstice. |
| Third interstice content | Third split earth conductor | Protected 24E9LWL optical element | The defining structural difference — and the source of the K in the designation. |
| Data capability | None | 24 singlemode fibres | Automation, CCTV, remote operation and TOS links travel inside the power cable. |
| MV system, insulation, field control | 6/10 (12) kV, EPR, semi-con layers | 6/10 (12) kV, EPR, semi-con layers | The medium voltage system is identical — termination practice carries over. |
| Mechanical rules | ±25°/m, 20/30 N/mm², 10×D moving | ±25°/m, 20/30 N/mm², 10×D moving | The hybrid retains the full high-to-extreme mechanical duty class. |
| Termination scope | MV terminations only | MV terminations + FO splicing / FORJ | The hybrid adds an optical workstream to installation and maintenance planning. |
10.2 One combined reel vs two separate reeling systems
The alternative to a hybrid cable is a second, independent fibre-optic reeling cable with its own reel, drive, guidance and slip-ring/FORJ assembly. The comparison below summarises the system-level trade-off that crane builders and terminal engineers actually decide on.
| System criterion | Two separate reels (power + FO) | One XPRT-LWL hybrid reel |
|---|---|---|
| Reels, drives, guidance systems | 2 of each — duplicated procurement and mounting space | 1 of each |
| Synchronization | Two reels must track the same travel profile without tension conflicts | Not required — one cable, one tension control |
| Moving failure points | Doubled (two cables, two reel drives, two guidance paths) | Minimised |
| Inspection and maintenance objects | Two reeling systems on every inspection plan | One reeling system |
| Spare cable stocking | Two cable types, two reels of spares | One cable type |
| Single-point-of-failure consideration | Power and data fail independently | One cable carries both — mitigated by 24-fibre redundancy and disciplined cable management |
| Replacement event | Cables replaced on independent schedules | One replacement renews power and data simultaneously |
Honest counter-argument
Engineering argument: the hybrid concentrates risk — mechanical destruction of the one cable interrupts both power and communication. The engineering response is threefold: the cable is built to the highest mechanical duty class of the family; the 24-fibre count provides internal redundancy against partial optical damage; and on a crane that loses its power cable, the machine stops anyway — a surviving separate data cable on a dead crane has limited operational value. For most crane applications, the consolidation argument therefore dominates, which is why the hybrid architecture has become the reference solution for automated and remotely operated cranes.
10.3 Boundary check against the 8.7/15 kV reeling family data
Reading the 6/10 kV XPRT-LWL dimensional data against the 8.7/15 kV (N)TSCGEWOEU family data discussed in this article series gives a useful directional check — noting that the two designs differ in both voltage class and interstice content, so this is a trend comparison, not a like-for-like one.
| Power core size | 6/10kV XPRT-LWL: max OD mm / weight kg/km | 8.7/15kV power-only: max OD mm / weight kg/km | Reading |
|---|---|---|---|
| 3×70 | 55.0 / 5000 | 56.0 / 5160 | Thinner 6/10 kV insulation outweighs the added optical element. |
| 3×150 | 67.2 / 8700 | 69.9 / 8630 | Weights converge — the optical unit and earth arrangement offset the insulation saving. |
| 3×240 | 80.7 / 13410 | 81.3 / 13300 | Near parity in both diameter and weight. |
| 3×300 | 89.2 / 15880 | 89.2 / 16350 | Identical OD; the 15 kV insulation wall dominates weight at the top of the range. |
The practical conclusion for reel and structure designers: adding a 24-fibre optical subsystem inside the 6/10 kV cable costs essentially nothing in diameter and weight compared with stepping the same construction up one voltage class — the reel, sheave and counterweight design space is barely touched by the data capability.
Selection framework
11. How to Select a PROTOLON XPRT-LWL (N)TSKCGEWOEU 6/10KV Class Cable
Selecting an opto-power reeling cable means verifying three systems at once: the medium voltage power system, the mechanical reeling system and the optical communication system. Cross-section and ampacity alone are never sufficient.
| Selection dimension | Data to confirm | Decision it drives |
|---|---|---|
| System voltage | Is the supply a 6/10 kV system with Um within 12 kV? | Confirms the 6/10 (12) kV class applies; higher systems need the 8.7/15 kV family. |
| Load current | Continuous current, duty cycle, ambient temperature, installation method. | Selects the 25–300 mm² cross-section. |
| Travel speed | Gantry reeling speed; whether it exceeds 240 m/min. | Above 240 m/min, manufacturer consultation is recommended. |
| Dynamic tension | Starting, braking, acceleration, reel tension and cable self-weight on the lift. | Checked against max tensile and acceleration tensile values per size. |
| Torsion path | Multi-plane direction changes and accumulated twist. | Verified against the ±25°/m rule. |
| Bending geometry | Reel core diameter, sheave diameters, roller pitch vs cable OD. | 6×D fixed, 10×D moving, 20×D between S-type direction changes. |
| Environment | Oil, ozone, UV, seawater, salt mist, outdoor exposure. | Confirms the PROTOFIRM-class PCP > 5GM5 sheath suitability. |
| Low temperature | Minimum temperatures of fixed and moving sections. | Verify fixed sections at -50°C and moving operation at -35°C. |
| MV termination | Semi-con stripping, screen treatment, earthing, stress control. | Easy-strip semi-conductive NBR supports reliable field termination. |
| Optical system | Fibre demand, redundancy concept, FORJ/splice losses, link budget. | Confirms 24×E9 capacity and the end-to-end attenuation budget. |
Engineer FAQ
12. Frequently Asked Engineering Questions
Question 1 — What is PROTOLON XPRT-LWL (N)TSKCGEWOEU 6/10KV?
Answer: It is a flexible 6/10 (12) kV medium voltage reeling cable for high to extreme mechanical stresses, with an integrated optical element of 24 singlemode E9 fibres. It supplies medium voltage power, protective earth and a fibre-optic data backbone to fast-moving container cranes and large mobile equipment from a single motorized reel.
Question 2 — What does 24E9LWL mean in the construction code?
Answer: 24 is the fibre count; E9 identifies singlemode fibre of the 9/125 µm class (ITU-T G.652 family); LWL is the German abbreviation for Lichtwellenleiter — optical fibre. So 1x(24E9LWL) means one protected optical unit containing 24 singlemode fibres.
Question 3 — Why integrate fibres into the medium voltage cable instead of running a separate fibre-optic reeling cable?
Answer: One hybrid reel replaces two complete reeling systems: one reel, one drive, one guidance path, one inspection object and one spare cable type instead of two of each, with no synchronization problem between independent reels. Optical fibre is dielectric and EMI-immune, so it coexists with the medium voltage cores without any interference penalty.
Question 4 — What bending radii apply, and do the fibres change them?
Answer: The family rules per VDE 0298-3 apply: 6×D fixed, 10×D moving, 20×D between S-type direction changes. The optical element is designed to live within these same limits — but the limits become doubly important, because an undersized roller produces measurable macrobending attenuation in the fibres long before it produces visible damage to the sheath.
Question 5 — How is the optical element terminated on a motorized reel?
Answer: The power cores terminate through the reel slip-ring assembly; the fibres pass through a fibre-optic rotary joint (FORJ) on the reel axis or, depending on reel design, through a free inner length to a drum-mounted splice box. Both ends are fusion-spliced into splice cassettes and patched onward with standard singlemode connectors. FORJ and splice losses must be included in the optical link budget.
Question 6 — What is the structural difference from a standard (N)TSCGEWOEU 6/10kV?
Answer: In the standard cable, three split earth conductors fill the three interstices (x/3 notation). In the XPRT-LWL hybrid, the earth is concentrated into two split conductors in two interstices (x/2 notation) and the third interstice carries the protected 24-fibre optical element. The medium voltage insulation system, field control layers and mechanical duty class are the same.
Question 7 — Can it operate at high travel speeds and low temperatures?
Answer: Gantry reeling operation has no general speed restriction; above 240 m/min, manufacturer consultation is recommended so that reel tension, sheave geometry and acceleration profiles can be verified. The flexible operation boundary is -35°C ambient (fixed sections -50°C); for arctic-class projects below this boundary, the design should be confirmed with the manufacturer at specification stage.
Feichun Engineering View
PROTOLON XPRT-LWL (N)TSKCGEWOEU 6/10KV represents the consolidation logic of modern crane electrification: 6/10 (12) kV medium voltage power, split protective earth and 24 singlemode E9 optical fibres engineered into one reeling cable rated for high to extreme mechanical stress. Its construction — very finely stranded tinned class FS conductors, semi-conductive EPR field control, high-stress EPR insulation, easy-strip semi-conductive NBR, two split earths plus a strain-decoupled optical element in the interstices, sandwich PCP inner sheath, polyester anti-torsion braid and PCP > 5GM5 outer sheath — keeps the full ±25°/m torsion and 20/30 N/mm² tensile capability of the family while adding an EMI-immune, future-proof data backbone at almost zero cost in diameter and weight. For STS, RMG and RTG-E cranes, ship unloaders and automated terminals, selection should verify the power system (voltage, 17 kV test level, ampacity), the mechanical system (dynamic tension, reeling speed, 10×D moving radius, S-type spacing, torsion, low temperature, sheath environment) and the optical system (fibre demand, FORJ and splice losses, link budget) together — because in an opto-power reeling cable, all three systems share one cross-section and one service life.
